public AbstractFilter() 
{
        translationTable = latin1TranslationTable;
        specialsTable = noSpecialsTable;
}

 public  void readFromReader(Reader in) throws IOException 
{
        char buf[];
        int count;
        buf = new char[2048];
        while(true) {
            count = in.read(buf);
            if (count <  0)
                break;
            for (int i = 0; i <  count; i++) {
              this.write(buf[i]);
            }
        }
}

 public  void readFromStream(InputStream in) throws IOException 
{
      int i;
      noSpecialsTable = new boolean[256];
      for (i = 0; i <  256; i++)
        noSpecialsTable[i] = false;
      allSpecialsTable = new boolean[256];
      for (i = 0; i <  256; i++)
        allSpecialsTable[i] = true;
      latin1TranslationTable = new char[256];
      for (i = 0; i <  256; i++)
        latin1TranslationTable[i] = (char)i;
        byte buf[];
        int count;
        buf = new byte[16384];
        while(true) {
            count = in.read(buf);
            if (count <  0)
                break;
            this.write(buf, 0, count);
        }
}

A convenience method that reads text from a FileInputStream and writes it to the receiver. The format in which the file is read is determined by the concrete subclass of AbstractFilter to which this method is sent.

This method does not close the receiver after reaching EOF on the input stream. The user must call close() to ensure that all data are processed.

 public  void write(int b) throws IOException 
{
      if (b <  0)
        b += 256;
      if (specialsTable[b])
        writeSpecial(b);
      else {
        char ch = translationTable[b];
        if (ch != (char)0)
          write(ch);
      }
}

Implements the abstract method of OutputStream, of which this class is a subclass.

 public  void write(String s) throws IOException 
{
      int index, length;
      length = s.length();
      for(index = 0; index <  length; index ++) {
        write(s.charAt(index));
      }
}

Hopefully, all subclasses will override this method to accept strings of text, but if they don't, AbstractFilter's implementation will spoon-feed them via write(char).

 abstract protected  void write(char ch) throws IOException
Subclasses must provide an implementation of this method which
accepts a single (non-special) character.

 public  void write(byte[] buf,
    int off,
    int len) throws IOException 
{
      StringBuffer accumulator = null;
      while (len  > 0) {
        short b = (short)buf[off];
        // stupid signed bytes
        if (b <  0)
            b += 256;
        if (specialsTable[b]) {
          if (accumulator != null) {
            write(accumulator.toString());
            accumulator = null;
          }
          writeSpecial(b);
        } else {
          char ch = translationTable[b];
          if (ch != (char)0) {
            if (accumulator == null)
              accumulator = new StringBuffer();
            accumulator.append(ch);
          }
        }
        len --;
        off ++;
      }
      if (accumulator != null)
        write(accumulator.toString());
}

Implements the buffer-at-a-time write method for greater efficiency.

PENDING: Does write(byte[]) call write(byte[], int, int) or is it the other way around?

 abstract protected  void writeSpecial(int b) throws IOException
Subclasses must provide an implementation of this method which
accepts a single special byte. No translation is performed
on specials.